question_answer

A man standing near a cliff with a seconds pendulum fires a gun when the pendulum is at the mean position and hears the echo when it just reaches the extreme position. If the speed of sound is \[340m{{s}^{-1}}\], calculate his distance from the cliff.-

A)  80 m                                    

B)  85 m

C)  75 m                                    

D)  70 m